Another star has become embroiled in a widening K-pop sex scandal that has sent shock waves through an industry known for its singers’ squeaky clean images.

In the space of two days, singer-songwriter Jung Joon-young and BIGBANG boy band member Seungri have both announced their retirement from show business.

Jung, 30, on Wednesday admitted filming himself having sex and sharing the footage without his partners’ consent while Seungri – real name Lee Seung-hyun – is embroiled in a sex-for-investment criminal investigation.

Jung, who was in the middle of shooting a reality TV show in the US, cut short his schedule and returned home on Tuesday, a day after broadcaster SBS reported that he made and shared porn videos filmed without the consent of more than 10 women he slept with over a period of eight months from late 2015.

“I admit to having committed all the wrongs that have been reported. I filmed women without their consent, spread (the films) in chat rooms. I did these activities without feeling any guilt,” he said in a statement.

“Throughout the rest of my life, I will repent on my immoral and illegal acts that constitute crimes,” he said, adding he would drop all TV programmes and stop activities as an entertainer.

The star, best known for his part in KBS variety show 2 Days & 1 Night, was due to be questioned by police on Thursday.

Filming a person’s body without consent can be punished with a prison term of up to five years or a fine of 30 million won (US$26,500) and the crime of distributing such photos or videos without consent is subject to five years in prison or a 30 million won fine.

South Korea has been battling a growing epidemic of so-called molka – spycam videos which largely involve men secretly filming women and sharing the illicit content with others.

But K-pop stars generally cultivate clean-cut images – and are actively promoted by the South Korean government as a key cultural export.

Many face tremendous pressure to look and behave perfectly in an industry powered by so-called “fandoms” – groups of well-organised admirers at home and abroad who spend enormous amounts of time and money to help their favoured stars climb up the charts and attack their perceived rivals.

With fortunes at stake they would have more to lose than most by being embroiled in a scandal, even after a wave of #MeToo accusations in the still socially conservative South over the past year.

Lee Moon-won, a pop-culture critic in Seoul, said the multilingual Seungri – who has multiple business interests – was popularly seen as “ideal cultural export”.

“Most of his fans would agree that Seungri is an exceptionally hard working star,” said Lee.

“On top of his singing career, he somehow mastered Japanese and Chinese, which made him a very useful member whenever BIGBANG visited those countries.

“Learning two foreign languages while being a K-pop star is definitely not an easy thing.”

Seungri was interviewed by police at the weekend over accusations he lobbied potential investors by offering them the services of prostitutes at nightclubs in Seoul’s posh Gangnam district.

The 29-year-old is also linked to a police investigation into Burning Sun, a nightclub where he was a public relations director, where staff are alleged to have filmed women with hidden cameras and used alcohol and drugs to sexually assault them.

Before the scandal, Seungri had been nicknamed the “Great Seungsby” after the protagonist of the Scott Fitzgerald novel The Great Gatsby, for his good looks, his seemingly successful business and the lavish parties he had thrown.

“It’s ironic how Seungri and Gatsby turned out to have more things in common after the scandal broke,” Lee said.

“Both have engaged in illicit and corrupt activities to gain fame and wealth.”

Reaction among BIGBANG fans has been divided, some expressing anger and disappointment, others disbelief and support.

Some overseas admirers posted online photographs of flowers and a hand-written note saying “I’ll wait for you on this flower road” – a BIGBANG lyric.

Another tweeted that they did not want to believe the accusation, adding: “I’m tired of all this and in pain. I admired Seungri for a long time and he made me smile in my worst days.”

But a group of South Korean fans urged his expulsion from the band, saying he had “significantly damaged the team’s reputation”.

For South Korean women’s activists, the scandal is unsurprising.

As well as secretly filming women in schools, toilets and offices, “revenge porn” – videos men take of themselves having sex with their exes or partners filmed without the women’s consent – is believed to be equally widespread.

In a society where patriarchal values are still deeply ingrained, circulation of such content can significantly damage a woman’s reputation.

According to Han Sol, an activist at Flaming Feminist Action, spycam videos have long been watched and shared by South Korean men as a form of entertainment and a way to strengthen their “brotherly ties”.

Last year, Seoul several times witnessed thousands of women protesting against spycam videos as part of the country’s ongoing #MeToo movement.

“This case just shows that male K-pop stars are no exception when it comes to being part of this very disturbing reality that exploits women,” said women’s rights activist Bae Bok-ju.